Indian Kaveri Turbofan’s Last Mile Problem: A Mystery Noise

Decayed performance at high altitude, insufficient thrust, excessive weight. Some of the problems the DRDO has reported on its Kaveri turbofan engine, a project in development for nearly three decades. It has now emerged that an unexpected ‘noise’ during high power trials has all but stalled the programme in what the team believes is its last mile. Detailed analyses over the last two years have failed to narrow down the nature of cause of the noise, and scientists are also unable to tell if the noise is an influence aerodynamic performance. What Livefist can confirm is that the phenomenon is only the latest in a series of complications that have bedeviled the Kaveri. The noise the five engines specimens make in high throttle regimes is a key issue being placed before France’s Snecma for the remaining path to certification. Apart from the noise in the high throttle spectrum, scientists have also been grappling with a flicker, indicating inconsistent combustion or fuel transmission, when the afterburners is engaged.

On Jan 3 this year, the Safran Group created and advertised for the new position of Director for the Kaveri engine programme.

The good news for the programme is that the DRDO has been given a virtual carte blanche to channelise offsets from the Indian Rafale deal to resurrect the Kaveri. Snecma, a partner in the Rafale programme, builds the Rafale’s twin M88 turbofan engines. Under the terms of the partnership finalised late last year, Snecma is working to modify, certify and integrate the Kaveri on a Light Combat Aircraft airframe before 2020. A later phase in the partnership will involve modifications on the Kaveri for a twin configuration on India’s AMCA fifth generation fighter concept and an altered non-reheat version for the Ghatak UCAV. It is not clear if the Snecma partnership will stretch to the concept Manik mini-turbofan being developed for UAVs and cruise missiles. One of the Kaveri specimens was on display at the recent Aero India show.

There are important implications of the Snecma-DRDO partnership on the Kaveri engine. A Kaveri engine sporting potential commonality with the Snecma M88 could be compelling factor in how India chooses its next fighter jets, both for the Indian Air Force and Indian Navy. Those implications, at any rate, would be clearer only once the Kaveri proves itself at every level of performance and envelope. It’s useful to break down the state of play with the new Kaveri in the projected mix.

LCA Mk.1/1A: Currently powered by GE 404. Intended to be powered by modified DRDO/Snecma Kaveri, with first integration aimed for by 2020.

Rafale: Powered by twin Snecma M88 turbofans.

LCA Mk.2: Two of eight GE F414-INS6 turbofan engines were delivered last month to keep the programme rolling. The future of the Mk.2, though, remains uncertain. If the modified DRDO/Snecma Kaveri can be uprated enough to meet Mk.2 demands, it could change things. For the moment, this doesn’t appear to be on the cards.

IAF Single-Engine Fighter: Either the GE F414 (on the Gripen E) or the GE F110/Pratt&Whitney F100 (on the F-16).

Indian Navy Multirole Carrier Fighter: A toss-up, effectively, between the Snecma M88 and GE F414.

AMCA: Intended to be powered by modified DRDO/Snecma Kaveri in twin engine configuration. But this remains in the air for the moment. There are other suitors, notably Boeing’s aggressive pitch that pushes the enhanced GE F414 supercruise capable engine for the AMCA, an engine family that Boeing’s Super Hornet shares with the Saab Gripen E.

GHATAK UCAV: DRDO/Snecma Kaveri modified for non-reheat stealth operations. The Government is clear at this stage that it doesn’t want a foreign powerplant on the sensitive programme.

5 Comments

bharat

“One way to improve performance and fuel economy is to increase the compression ratio inside the engine. The compression ratio refers to the amount of fuel and air squeezed into the combustion chamber. When this ratio is higher, it uses fuel more efficiently.Most of the engines on the road today mix the fuel and air before introducing them to the combustion chamber. In a direct-injected engine, highly pressurized fuel is squirted directly into the combustion chamber at the top of the piston’s stroke, near the spark plug.

Since this creates quite a bit of pressure in the combustion chamber, direct injection can cause knocking, too, just like higher compression ratios. Ford Motor Company has solved this problem by combining direct injection with turbo charging, which uses exhaust gases to boost performance.”

bharat

”
The problem with higher compression ratios is usually a knocking sound in the engine, which occurs when temperature and pressure are too high in the chamber and the air and fuel mixture ignites too early. Higher octane gas on its own can solve some of this problem, but Mazda has developed a longer exhaust manifold that reduces the temperature and the chance of engine knock. The SKYACTIV-G system also has a faster combustion time, which means the air-fuel mixture ignites properly before the temperature can build up and knocking begins.

All this engine technology — as well as weight-saving materials and a new transmission — mean 15 percent lower fuel consumption and emissions and 15 percent more torque. And increased torque translates into more One way to improve performance and fuel economy is to increase the compression ratio inside the engine. The compression ratio refers to the amount of fuel and air squeezed into the combustion chamber. When this ratio is higher, it uses fuel more efficiently.Most of the engines on the road today mix the fuel and air before introducing them to the combustion chamber. In a direct-injected engine, highly pressurized fuel is squirted directly into the combustion chamber at the top of the piston’s stroke, near the spark plug.

Since this creates quite a bit of pressure in the combustion chamber, direct injection can cause knocking, too, just like higher compression ratios. Ford Motor Company has solved this problem by combining direct injection with turbo charging, which uses exhaust gases to boost performance.”

shankar

it takes 15 years to test a engine……
even fir usa or france or russia…..
looking at this rate the way we delayed tejas mk1 for 3 decades with even 55% local snd 45% forign components still ioc clearence not achived